Eye color defect phenomenon (for example red eyes) is usually observed in images captured in low ambient illumination conditions. Typically, in low ambient illumination conditions, the pupils of eyes of the subject are wide open, and when the flash light hits the eye, an internal reflection from vascular membrane behind the retina of the subject's eyes occurs. In humans, such internal reflections often result in unnatural reddening of the pupil region of the eyes thereof. However, in other types of animals, other colors may result, such as golden eyes and the like.
Apart from low ambient illumination levels, various other factors also contribute to the occurrence of the red eyes. Such factors may include small angle between the flash of the image capturing device and the lens thereof, proximity of the candidate to the image capturing device, and the like.
Typically, in order to avoid appearance of the red eyes in the images, image capturing devices are utilized that may include a secondary lamp or light that is flashed prior to capturing the image. This lamp exposes the subject's eyes to light for few seconds before exposure to the actual flash light, thereby giving pupils enough time to contract. In some instances, instead of one full flash, the image capturing device provides multiple pre-flashes that may produce the same effect as being produced by single flash of the secondary lamp. However, such devices may introduce a time delay between the first flash and actual capturing of the image, due to which the subject may deviate from a posed position before the actual image is captured.
Further, user intervention may be required in correcting the red eye problem in the images by processing the clicked image to remove the color defects from the eyes. However, such user intervention in identifying and removing red-eyes may prove cumbersome and inefficient. Furthermore, due to user intervention, the red eyes may be misinterpreted as non-red eye regions, and vice-versa. Moreover, such devices may often miss out on other known eye color defects such as golden eyes, and the like. Accordingly, the currently available techniques provide little use in detecting eye color defects of varying saturation and brightness.